1. Field of the Invention
The present invention generally relates to a method and system of image contrast correction, and more particularly relates to a method and system of liquid crystal display image contrast correction with Fuzzy theory.
2. Description of the Prior Art
Nowadays, Liquid Crystal Display (LCD) is a kind of monitor apparatus with lots of advantage, such as, light, low volume, low power consumption, low radiation, low glitter and can save more space. However, the LCD monitor has a major disadvantage on image display is low contrast. Low contrast cause the image quality of LCD can't contend against the vivid image quality displayed from the plasma display panel and the traditional CRT monitor. The root cause of low contrast is because the liquid crystal can not completely covers the backlight. As this result, light leakage phenomenon occurs when the LCD shows the black image. At the same time, when the white image doesn't have enough illumination neither due to low luminance, the contrast of LCD will become quite low. One of the prior arts to solve this problem is to analysis the input signal by cumulative distribution function (CDF). However, CDF needs about 1˜2 frame time to calculate the data, it can not display the corrected image in real time and needs lots of electric storage apparatus to calculate the function.
One of the other prior arts to solve this problem is modifying the driver voltage of source driver IC to force gray scale shows brighter or darker image. This method doesn't need extra production cost and won't occupy the hardware space. However, part of response speed of the digital to analog converter (DAC) of external hardware circuit may limit the resolution of the image and DAC has large power consumption also.
The contrast of LCD determines the image quality, said, how to make LCD has better color quality by correct the image within finite luminance is a big issue.